Even after more than 170 years since the issue of the first Zurich stamps there are moments, when widely recognized and acknowledged findings are suddenly challenged. Even Jakob Gnägi, once a curator with the Bern Postal Museum (today’s Museum of Communication) and certainly one of the best connoisseurs of Old Zurich stamps, most likely assumed that this sheet field of the Zurich 6 had a major flaw on the top left, the so-called “great retouching”. He probably reviewed hundreds of these Zurich 6 stamps, considering the remarkable inventory of the Postal Museum and his work for the benchmark “Die Zürcher Kantonalmarken von 1843” (The 1843 Zurich Cantonal Stamps) in 1984. Without a doubt, he had a special focus on the most remarkable of plate flaws on the Zurich 6, the 98th stamp on each sheet.
Technically it would be correct to talk about a stone flaw, as the stamps were printed using lithographic stones instead of printing plates. It would be meaningless to change the expression, considering that flaws on the Durheim issues are also referred to as plate flaws.
During my 50+ years of professional experience with classic Swiss stamps, several dozens of stamps from the 98th field went through my hands. There was not a single time when said “great retouching” was not located on the top left of the stamp. Recently however, I was offered a Zurich 6 showing all characteristics of the 98th field but… the “great retouching” was missing!
While studying this piece thoroughly, one will recognize that there are no signs of retouching in that top left place, however a printing imperfection can be noticed – quite like the one on the 39th sheet field. This imperfection appears to stem from immediately after the fabrication of this stone which was then used to print the stamps. It is possible that some object fell on the stone and caused this kind of damage to the black grid of lines. The crude repair work that has been done afterwards suggests (again per Gnägi) that no expert, i.e. no lithograph could have done this work. It seems that the flaw was discovered at the print shop and then rudimentarily fixed. Furthermore, it is safe to assume that this repair work became inevitable very soon, probably after printing the first few sheets which would usually undergo a strict quality check. We know that the “great retouching” occurs only once per sheet. Therefore, it is 100 times scarcer than a regular Zurich 6. Assuming a print run of about 1,800 sheets with 100 Zurich 6 stamps each (per study by Gnägi, Senn) and also that just a few sheets were produced without the retouching on the 98th stamp, said stamp would be incomparably scarcer than the 98th stamp bearing the retouching.
A long and well-grounded article for the 100th anniversary of the first Swiss stamps by Max Hertsch was released in the February 1943 issue of the Bern Stamp Journal, showing images of several stages of the retouching. The first image shows an imperfection, but no work seems to be done to it yet. It is too unclear to tell for sure. Hertsch however describes this original condition as retouched, meaning that smaller work has already been done beforehand. He is also writing that he never saw a single stamp of the 98th field that did not show any signs of retouching.
Isn’t this living proof for the fact that interesting discoveries are possible more than 170 years after the first classic Swiss stamps? You may start investigating now! Along print runs that “great retouching” underwent several changes due to the spot warping and weakening under pressure. It seems appealing to gather material illustrating the different states, as the Zurich 6 is mostly lacking such prominent interesting plate flaws or retouching work.